The present invention relates generally to guidance systems for tractor-drawn implements and, more specifically, to guidance systems which are adaptable to fit both of the common-sized tractor three-point quick hitch configurations that are presently in use.
A well recognized problem of modern mechanized agriculture is the potential for damaging crops by the lack of proper operator control over tractor-drawn implements. Trends in farming call for the use of single tractors to cultivate more and more crop rows per pass, and the chances increase for crop damage due to minor steering errors on the part of the operator.
Sophisticated implement and tractor guidance systems have been disclosed in an effort to provide an effective solution to this problem. One such device is disclosed in my U.S. Pat. No. Re. 34,080, which discloses a row following guidance device which will connect the left and right sides of the forward end of an implement to a tractor and which will adjust the length of each left and right connection such that the implement will follow the crop rows in spite of lateral deviations of the tractor relative to the crop rows. The device is mounted on a conventional quick-hitch so that it may be used with a variety of different implements. A row following weight or wand controls a steering valve upon any deviation from the alignment of the implement within the crop rows, and the steering valve corrects the deviation by lengthening one connection between the tractor and the implement and shortening the other connection. The row following weight or wand is mounted for movement independent of the implement so that the implement may be raised or lowered without affecting its operation.
One drawback of the existing guidance device is that it is very cumbersome to adjust to accommodate tractor and implement hitches of both wide and narrow designs, both of which are in common use, and may be used by any one grower. Presently, when such a conversion is needed, the guidance device must be almost totally disassembled and the central crossmember replaced by one of different length.
Thus, it is a first object of the present invention to provide an improved adjustable guidance device wherein the majority of the control and actuation system is located on a central cross member for ease of operation and maintenance.
It is another object of the present invention to provide an improved adjustable guidance device which is readily convertible between operation on wide and narrow tractor or implement hitches.
A further object of the present invention is to provide an improved adjustable guidance device wherein a positive power source is used to minimize componentry and to eliminate an excessive number of wear points.
Yet another object of the present invention is to provide an improved adjustable guidance device for row crop use wherein adjustment can be made from wide to narrow tractor or implement hitches using the existing components.
It is still another object of the present invention to provide an improved adjustable guidance device for row crop use wherein accurate and positive control is maintained over the position of each end of the device relative to the rear of the tractor.